Advanced Exergy Analysis in the Dynamic Framework for Assessing Building Thermal Systems

This work applies the Dynamic Advanced Exergy Analysis (DAEA) to a heating and domestic hot water (DHW) facility supplied by a Stirling engine and a condensing boiler. For the first time, an advanced exergy analysis using dynamic conditions is applied to a building energy system. DAEA provides insights on the components’ exergy destruction (ED) by distinguishing the inefficiencies that can be prevented by improving the quality (avoidable ED) and the ones constrained because of technical limitations (unavoidable ED). ED is related to the inherent inefficiencies of the considered element (endogenous ED) and those coming from the interconnections (exogenous ED). That information cannot be obtained by any other approach. A dynamic calculation within the experimental facility has been performed after a component characterization driven by a new grey-box modelling technique, through TRNSYS and MATLAB. Novel solutions and terms of ED are assessed for the rational implementation of the DAEA in building energy installations. The influence of each component and their interconnections are valuated in terms of exergy destruction for further diagnosis and optimization purposes.BMWi, 03ET1218B, Anwendung exergiebasierter Methoden zur Verbesserung von Gebäudeenergiesysteme

Optimization and plasticity in disordered media

We study the plastic yielding of disordered media using the perfectly plastic random fuse model. The yield surfaces are shown to be different from those obtained minimizing the sum of the local yield thresholds, i.e. the so-called minimum 'energy' surfaces. As a result, the global yield stress is lower than expected from naive optimization and the difference persists as the sample size increases. At variance with minimum energy surfaces, height-height fluctuations of yield surfaces exhibit multiscaling. We provide a theoretical argument that explains how this behavior arises from the very different nature of the optimization problem in both cases.Comment: Accepted for publication in Physical Review Letter

From Brittle to Ductile Fracture in Disordered Materials

We introduce a lattice model able to describe damage and yielding in heterogeneous materials ranging from brittle to ductile ones. Ductile fracture surfaces, obtained when the system breaks once the strain is completely localized, are shown to correspond to minimum energy surfaces. The similarity of the resulting fracture paths to the limits of brittle fracture or minimum energy surfaces is quantified. The model exhibits a smooth transition from brittleness to ductility. The dynamics of yielding exhibits avalanches with a power-law distribution

Nominalized clauses, clausal arguments and agreement

Strict minimalist assumptions require adopting the hypothesis that argument clauses and nominalized clauses are assigned Phi features. The data examined suggest that the interpretable Phi content of these arguments is specified as [-P, -N, -G]. We conclude that all arguments (of the clausal or of the nominal types) are subject to the operation Agree with a functional category. All arguments behave alike as far as abstract computational operations is concerned. The computational component is blind to the concrete values of the features of the arguments related to functional categories.Supòsits estrictament minimalistes requereixen que s'adopti la hipòtesi que les oracions en funció d'argument i les oracions nominalitzades tinguin assignats trets Phi. Les dades que s'examinen suggereixen que el contingut Phi interpretable d'aquests tipus d'arguments s'especifica amb els valors [-P, -N, -G]. Es conclou que tots els arguments (tant de tipus oracional com nominal) se sotmeten a l'operació Concorda amb una categoria funcional. Tots els arguments es comporten de la mateixa manera respecte a les operacions computacionals abstractes. El component computacional no té en compte els valors concrets dels trets dels arguments que es relacionen amb categories funcionals

A Mark of Specificity in Indefinite Nominals

En aquest article es defensa la proposta de Diesing (1992) que els indefinits no poden rebre un tractament uniforme de variables o de quantificadors. L'evidència empírica a favor d'aquesta afirmació es basa en la posició dels adjectius qualificatius en els sintagmes determinants indefinits del català. Els adjectius qualificatius apareixen en posició prenominal si l'indefinit és específic, i en posició postnominal si és inespecífic. Es mostra, per tant, que la distinció entre indefinits específics i indefinits inespecífics té correlats sintàctics en llengües romàniques com el català

Possessive Pronouns in Catalan and the Avoid Pronoun Principle

En els Sintagmes Determinants (SDs) en català poden aparkixer dos tipus d'elements pronominals: el pronom possessiu i el pronom fort. Aquests elements difereixen en distribució, comportament sintàctic i propietats denotatives. En aquest estudi es mostra que l'alternança possessiu/pronom fort en les construccions nominals es paral·lela a l'alternanca pro/pronom fort en les estructures oracionals. Proposem que aquest paral·lelisme és una conseqüència de l'aplicació del principi "Eviteu el pronom" en els SDs i els SCs. Suggerim que "Eviteu el pronom" s'ha de concebre com un principi gramatical que imposa estratègies d'economia en el contingut lèxic de les categories pronominals, no en el seu contingut fonològic tal i com s'ha assumit fins ara.Two types of pronominal elements may appear in Catalan Determiner Phrases (DPs): the possessive pronoun and the strong pronoun. These elements differ in distribution, syntactic behavior and denotative properties. In this study, it is shown that the altemation possessivelstrong pronoun in Catalan nominal constructions is parallel to the altemation pro lstrong pronoun in clausal structures. We propose that this parallelism follows from rhe application of the Avoid Pronoun Principle in Catalan DP and CP structures. We argue that Avoid Pronoun has to be conceived as a principle of grammar imposing economy strategies in the lexical content of the pronominal categories, but not in their phonological content as has customarily been assumed

El programa minimista en la teoria de principis i paràmetres

This paper intends to offer a general overview of the ideas that have been proposed in generative grammar in the last decade. The theoretical framework that supports them is summarized (the Principles and Parameters theory) and we explain some conceptual changes that the theory has undergone from its first formulation (known as the Government and Binding model) to the recent proposals (known as the Minimalist model). The changes introduced under the minimalist perspective obbey to the necessity of eliminating some theoretical artifacts by submitting to scrutiny some assumptions. The Minimalist view suggests that the only possible grammatical operations are the unavoidable ones that are triggered by the interaction of the linguistic system with other external systems